Cynology & Anatomy

Dorsal stripe in dogs: What the stripe on the back means

Der Aalstrich (auch Aalstreif oder dorsaler Streifen) ist eine dunkler pigmentierte Fellzone, die entlang der Rückenlinie des Hundes vom Nacken bis zum Rutenansatz verläuft — analog zum Aalstrich bei Wildeseln, Przewalski-Pferden und anderen primitiven Wildtieren. Beim Hund ist er ein atavistisches Fellmuster, das auf die Pigmentierungsgenetik der Vorfahren zurückgeht.

Eel stripe in dogs: what the stripe along the back means

What is the eel stripe in dogs?

The eel stripe (also called a dorsal stripe) is a more darkly pigmented area of coat that runs along the dog’s backline from the neck to the base of the tail — analogous to the dorsal stripe seen in wild asses, Przewalski’s horses, and other primitive wild animals. In dogs, it is an atavistic coat pattern that traces back to the pigmentation genetics of their ancestors.

The eel stripe is not a disease, not a defect, and not a breed marker in all dogs — in some breeds it is desired and described in the breed standard, while in others it appears as an individual pattern.

Background + scientific classification

Schmutz and Berryere (2007, Animal Genetics, PubMed 17397516) describe the genetic basis of coat color and patterning in dogs: dark dorsal stripes such as the eel stripe arise through the expression of the agouti signaling protein (ASIP) — the agouti locus regulates the distribution of eumelanin (dark pigment) and pheomelanin (red/yellow pigment) in the coat. Wild-colored (agouti/sable) dogs often show dark dorsal stripes due to a higher concentration of eumelanin along the topline.

Kerns et al. (2007, Genetics, PubMed 17237505) analyzed inheritance patterns in coat color and markings: dorsal stripes are part of a complex interaction system involving several color genes (A locus, K locus, E locus). In primitive and ancient breeds, the agouti pattern is more often preserved — these breeds more frequently show eel-stripe phenotypes.

Wayne and Ostrander (2007, Trends in Genetics, PubMed 17350132) describe the evolutionary background of domestic dog coat markings: domestication and selective breeding have led to enormous variation in coat color and pattern — but primitive breeds with little genetic change more often retain wild-type color patterns, including dorsal stripes. The dog genome project made it possible for the first time to systematically genotype these patterns.

Vitomalia position

The dorsal stripe is a fascinating relic of wolf ancestry — genetically archaic, aesthetically unmistakable. It is often unfamiliar to beginners in cynology and is sometimes confused with coat anomalies. In short: a normal part of certain breed appearances, not a medical finding.

When does a dorsal stripe become relevant?

  • When buying or assessing breeds in which it is a breed characteristic
  • In cynology and the show world (breed standard assessment)
  • Genetic breeding planning (coat pattern prediction)
  • Confusion with coat diseases (differential diagnosis)
  • Biological fascination: the dog-wolf connection in appearance

Practical application

Breeds with a typical dorsal stripe:

breed Dorsal stripe Status in the standard
Shikoku Pronounced Breed characteristic
Kishu Present Typical of the breed
Kai Ken Pronounced Breed characteristic (brindle pattern + dorsal stripe)
Basenji Slight to distinct Natural
Norwegian Elkhound Present Typical of the breed
Sable-colored GSD Variable Individual
Malinois (sable/fauve) Variable Individual

Distinguishing a dorsal stripe from coat diseases: - Dorsal stripe: evenly darker pigment, no scaling, no hair loss, no skin redness — normal coat phenotype - Dorsal Demodex-related baldness: uneven, hair loss, scaling, signs of inflammation → veterinarian - Pressure mark (back): linear baldness caused by mechanical friction → no dark pigmentation

In breeding: - The dorsal stripe is inherited according to agouti locus rules - Crosses with non-agouti parents (e.g. black dogs) can mask a dorsal stripe - Breeding goal: consult the breed standard to see which expression is desired

Common mistakes & myths

  • “The dorsal stripe indicates a wolf mix.” Not automatically — many purebred dogs with primitive genes carry a dorsal stripe. Mixed-breed dogs of all kinds can show it as well. It is not proof of wolf hybridization.
  • “My dog has a coat disease on the back.” If there is an evenly darker stripe without hair loss, scaling, or inflammation: it is most likely a dorsal stripe. True dorsal hair loss needs veterinary dermatological assessment.
  • “Only hunting dogs have a dorsal stripe.” No — it occurs in primitive spitz-type dogs, Asian herding dogs, Nordic breeds, and individual dogs of any ancestry.

Scientific status 2026

The genetics of the Agouti system in dogs is well characterized through the dog genome project. ASIP variants that promote dorsal stripe formation are more common in primitive breeds. Current research uses canine genome data to trace domestication pathways — coat patterns such as the dorsal stripe serve as genomic markers for relatedness to ancient dog breeds.

Frequently asked questions

What does a dorsal stripe mean in dogs?

It is a coat pattern — a darker pigment stripe along the topline, genetically regulated by the Agouti system. In certain breeds, it is a breed characteristic; in general, it is considered an atavistic legacy of the wolf lineage.

In which dog breeds does the dorsal stripe occur?

Common in primitive and Asian breeds (Shikoku, Kishu, Kai Ken), Nordic spitz-type dogs, and individually in sable-colored dogs of various breeds. Mixed-breed dogs with primitive genes can also show it.

Can a dorsal stripe indicate a disease?

A true dorsal stripe without hair loss, scaling, or inflammation is not a sign of disease. If the dark area along the back is accompanied by hair loss or skin changes, consult a veterinary dermatologist.

Related terms

Sources & further reading

  1. Schmutz, S. M., & Berryere, T. G. (2007). Genes affecting coat colour and pattern in domestic dogs: a review. Animal Genetics, 38(6), 539–549. https://pubmed.ncbi.nlm.nih.gov/17397516/

  2. Kerns, J. A., Cargill, E. J., Clark, L. A., Candille, S. I., Berryere, T. G., Olivier, M., … Barsh, G. S. (2007). Linkage and segregation analysis of black and brindle coat color in domestic dogs. Genetics, 176(3), 1679–1689. https://pubmed.ncbi.nlm.nih.gov/17237505/

  3. Wayne, R. K., & Ostrander, E. A. (2007). Lessons learned from the dog genome. Trends in Genetics, 23(11), 557–567. https://pubmed.ncbi.nlm.nih.gov/17350132/

Wissenschaftliche Einordnung

Schmutz and Berryere (2007, Animal Genetics, PubMed 17397516) describe the genetic basis of coat color and patterning in dogs: Dorsal dark stripes such as the dorsal stripe (eel stripe) result from the expression of the Agouti-signaling protein (ASIP) — the Agouti locus regulates the distribution of eumelanin (dark pigment) and pheomelanin (red/yellow pigment) in the coat. Wild-type (Agouti/Sable) dogs often show dorsal dark stripes due to higher eumelanin concentration along the backline.

Kerns et al. (2007, Genetics, PubMed 17237505) analyzed inheritance patterns in coat color and markings: Dorsal stripes are part of the complex interaction system of multiple color genes (A-locus, K-locus, E-locus). In primitive and ancestral breeds, the Agouti pattern is more frequently preserved — these breeds more often display dorsal stripe phenotypes.

Wayne and Ostrander (2007, Trends in Genetics, PubMed 17350132) describe the evolutionary background of domestic dog coat markings: Domestication and selective breeding have led to enormous variation in coat color and pattern — but primitive breeds with less genetic alteration more frequently retain wild-type patterns, including dorsal stripes. The Dog Genome Project first allowed systematic genotyping of these patterns.